12 inch dob vs 8 inch goto

[icebergahed]

12 inch dob vs 8 inch goto registered with this forum, in search for an answer. What would be the ideal for dso's not really thinking of astrophotography yet. Maybe snap shot or video. I like the ideas of goto's but know my way round the sky anyway. I've been pondering between 10/12 inch dob and 8/10 GEM reflector.

[Naemeth]

12 inch dob vs 8 inch goto registered with this forum, in search for an answer. What would be the ideal for dso's not really thinking of astrophotography yet. Maybe snap shot or video. I like the ideas of goto's but know my way round the sky anyway. I've been pondering between 10/12 inch dob and 8/10 GEM reflector.

If you have no problems moving the 12" dob, get the 12", the extra 4" will make a big difference.

Welcome to the forum by the way .

[Capricorn]

Well the Dobsonian does not need power and is over 2x more ligh gather.

If you intend any sort of imaging the it is basically useless.

A dobsonian is to me a one person scope, it is not easy to find something then hand the scope to someone else without the high chance that the second person loses the object.

At high magnifications things drift out of view fast.

The goto requires power, if an Alt/Az mount then planetary imaging is an option, if an equitorial then some DSO imaging is an option but not overly easy. I have assumed an 8" SCT ?

Easy for another person to see things and it tracks the object so easier to look at something for periods of time.

Really there seems little in it and would be a personal preference only - which do you actually want ?

I like goto's, I know where things are, but really I am quite happy for the scope to go off and point at something. Ocasionally I have one idea where it should go and it has another - they are the more interesting times. As in What the hell is going on?

[russ.will]

I had an 8" 200p on an HEQ5 Synscan and now have a 300p FlexTube Dob. For visual, the difference is not small.You see much more structure in the fainter fuzzies and the more obvious stuff like M42 gets hints of colour, that the 8" rendered as black and white.

Russell

[bomberbaz]

I cant honestly compare but the difference i noticed when I got my own 12" was absolutely amazing. Granted I only had a 130 previously, (which I have decided to keep) I was considering a 8 inch dob but i am go glad that i listened to the pursuasive voices on here, go for the 12.

Baz

[KenG]

Capricorn has summed it up very well.

[Skylook123]

I can comment from personal experience as I've grown through aperture, and technologies.

I started out with a 6" f/5 newtonian on a manual equatorial mount. I had to use slow motion controls to follow the target, but at that aperture and focal length, the need to adjust the view for earth rotation was trivial. I did, after a time, add motors for RA, DEC, and focuser. Wonderul fields, and I did not know what more aperture could bring.

After two years, my job required me to spend 3 out of 4 weeks in Arizona, while I lived in Virginia, so I bought a used 10" LX-5 telescope, an f/10 on simple tracking fork mount, in Arizona. The first time I used out under the dark desert skies at nearly 5000 feet elevation, I thought I had fallen into a pool of stars. Things that had been mere dots or smudges were real and, at first look, seemed like photos. At times, I added an f/6.3 focal reducer to get better fields of view for context and sacrificed some power.

Then all of my astronomy kit was stolen in a burglary. With the insurance money, I bought a 14" Celestron Starhopper tube dobsonian. Oh My, what a tremendous change. I could do wonderful things with galaxies, multiple stars, and solar system objects that were beyond the reach of the 10". Eventually, the burglars were caught and I was able to buy $5000 of my stolen equipment back from the insurance company (6" scope was missing) for less than $1000. At the same time, I began to get into public outreach.

Several years later I got the opportunity to do a three way swap of telescopes and gave up the 14" tube for an 18" truss dob. It was like I had fallen off the planet into the universe. So, in a 9 year period, I went from 6" to 10" to 14" to 18", and each was a tremendous leap in exposure to the night sky. The electronics of the LX-5 eventually failed, so it now resides on an Atlas EQ-G.

Although my personal observing is with the 18", since most of my observing time is now public outreach, about 90% of my time is with the 10" and full GOTO, for the convenience of the public. However, there are seven or eight events each year where I use the 18" with the public. Human powered, I use one of two eyepieces. Most of the time, a 19mm Panoptic which, at 120X, is perfect for the public viewing. And I only have to recenter the object in view every five or six viewers. This small effort, to me, is worth the look on the faces of the visitors as they see the Hercules Cluster, the Dumbbell Nebula, The Sombrero Galaxy, Albireo, Saturn, Jupiter, or any number of other spectacular views at 18" aperture. And if the seeing behaves and we are at our 7000 foot Grand Canyon Star Party Location, what a 9mm Panoptic will do was officially called, in a formal comment card to the Park headquarters, "a life changing experience". Yes, then I do have to recenter every four visitors, but again, it is worth the small effort. Plus, if not for that effort, I would truly be a couch potato.

My choice is to go for the largest affordable aperture, with the most of the investment in the mirror. But, that is my preference since I may observe over 30 objects on my personal nights and use digital setting circles for locating each object. For others, tracking and GOTO do become important considerations for extended study of individual objects and avoiding mind-numbing searches for new objects. Perfectly valid objectives. By the way, I also use the 10"/Atlas to track satellites as well as my five or six school events each month, and to me, the advantage is that I can set the height so all I need is a small stool and rotating the star diagonal for any sized observer. But if mostly adults will be my audience, the 18" is the winner. For my goals.

Best of luck on your choice; which ever way you go, don't look back and enjoy the moments you have with the equipment you have.

[Qualia]

Aperture will always win in the visibility - resolution - of astronomical objects, assuming diffraction-limitation, collimation, and seeing conditions. This does not imply that a small aperture instrument cannot provide excellent views of the heavens but looking at many sketches one does appreciate the advantage of bigger aperture. The bottom line is to use the instrument at your disposal to it's fullest potential. If it were me, and I didn't have a problem with carrying the gear and getting it about to a dark site, I'd shrug off GoTo and instead learn the skies and the art of star hopping and go for the biggest telescope possible

[brantuk]

If you're anything like me and want to have a scope that can view everything really well with an ability to either observe or image in wide field low power or narrow field high power or any combination thereof - then there's no other way than to get one of each type of scope.

[cotterless45]

The choice of gear depends on what you are able to see in your main location and how much time you get with clear skies. I learnt the skies with a 130P Heritage Dob.

A 10" Lightbridge opened up the view and is great to transport to darker skies. A lot of time was being spent on searching, often frustratingly without result. I bought an Heq5pro, this has made using scopes so much easier and an 8" Newt mounted gives views of most deep sky objects.

I'd go for the GOTO if I had to choose just one,a mount will give versatility on choice of scope to use

Nick.

[Mr Fiery Jack]

If you're anything like me and want to have a scope that can view everything really well with an ability to either observe or image in wide field low power or narrow field high power or any combination thereof - then there's no other way than to get one of each type of scope.

I concur. One scope won't do it all, sad but true.

The response to the aperture question amongst astro buffs will often be to buy the biggest scope you can, even if your 85 and live on the 16th floor of a block of flats with a dodgy lift and no transport IMHO your goto option is not worth sacrificing the extra 4 inches for.

[SplintUK]

I have a heq5 pro with 200pds and recently got a 10" skyliner dob with a telrad. I love that I can take the dob outside point it at something and look at it.

I so still use the goto setup -mainly for photography, but for visual the dob is quick, the goto means take it out, level the tripod, connect the mount, bring out the power pack, polar align the mount, mount the scope, balance the scope, check the mount polar alignment again, star align the scope, (find alignment stars that aren't behind the house, the trees or the hedge having to look up the ones I don't know by name - quite a lot of them- to see of they are going to work for me), get it all sorted, then accidentally kick the tripod and knock the alignment out, redo from start.

Times like these, you wish you'd started observing half an hour ago with the dob. Or had a concreted in pier base for the mount, ideally in an observatory. ;-)

I think the right answer is "get both, but get the dob first."

Hope that gives you good for thought if nothing else.

[Mr Fiery Jack]

I have a heq5 pro with 200pds and recently got a 10" skyliner dob with a telrad. I love that I can take the dob outside point it at something and look at it.

I so still use the goto setup -mainly for photography, but for visual the dob is quick, the goto means take it out, level the tripod, connect the mount, bring out the power pack, polar align the mount, mount the scope, balance the scope, check the mount polar alignment again, star align the scope, (find alignment stars that aren't behind the house, the trees or the hedge having to look up the ones I don't know by name - quite a lot of them- to see of they are going to work for me), get it all sorted, then accidentally kick the tripod and knock the alignment out, redo from start.

Times like these, you wish you'd started observing half an hour ago with the dob. Or had a concreted in pier base for the mount, ideally in an observatory. ;-)

I think the right answer is "get both, but get the dob first."

Hope that gives you good for thought if nothing else.

I don't have an issue with goto as an aid to observation (although its not my bag) is the set up time. I can set up my dob and my frac, have a quick session with the frac while the dob is cooling before having cup of coffee while watching the boys setting up up their GEM goto set ups....fascinating to watch them

[Eastridge]

Dob - we ( yes two of us can use it , we are well practiced at the handover routine now!) got one and now wouldn't go back to anything on a mount not only because you a high % for the mount not the aperture but also we just find the Dob easier to use.

Felt GOTO would have been money well spent if we didn't know the sky at all, but as you have to align it first etc. the 'point and view' nature of the Dob was the route for us.

[icebergahed]

I think im torn between the choice of a 8 inch which can goto objects and not showing as much detail compared to a 12 which would show me loads more but i would need to find the object and nudging to keep it in view. i suppose the answer is a go to 12 dob but my budget wont allow.

[icebergahed]

I suppose a 12 dob could always be upgraded onto a goto mount in the future if i was to roam into ttje realms of astrophotography much later.

[Mr Fiery Jack]

The sky is soooooo much easier than beginners think. What is the rush anyway, like anything worthwhile it just takes a little time to learn. Start with the easy stuff. The Orion Nebula, M32, M45, The ring Nebula, The double cluster, M13 and go from there. Every time you have a session just add one more target to the list.

[Mr Fiery Jack]

Sorry, that should have read M31 but while I am here you should go and buy yourself a copy of Turn Left at Orion, its a bit like flicking through a shopping catalogue.

[Budding Star Gazer]

i am pondering the same questions, apature v the ability to move into astrophotography later on without spending money on another scope with an EQ mount.

i was resolved to the orion sky quest 12i or 14i for observation only then i started looking at SCT & the likes for imaging but i want the best of both worlds observation with large apature and as good as i can afford for imaging.

as a result im looking at this http://www.telescopehouse.com/acatalog/Revelation-12--f-4-M-LRN-Optical-Tube-Assembly-OTA-2.html to which i will add an EQ mount, by time you purchase everything else you need i'd expect to spend the best part of £2000, for the same money you could get an LX90 8", a 10" RC set up or a 12/14" dob or an 8/10" SCT.

personally i think this will offer me the best of both for the money.

[Budding Star Gazer]

for a little more info on the above you can find the same tube at Altair astro, they are made by GSO

[Matt Scunthorpe]

I suppose a 12 dob could always be upgraded onto a goto mount in the future if i was to roam into ttje realms of astrophotography much later.

To mount a 12inch dob on a mount youd need an NEQ6 i believe which is £960 new. Depends how much budget you have in the future, as to your decision now.

[swamp thing]

1355663511[/url'>' post='1743248']

i am pondering the same questions, apature v the ability to move into astrophotography later on without spending money on another scope with an EQ mount.

i was resolved to the orion sky quest 12i or 14i for observation only then i started looking at SCT & the likes for imaging but i want the best of both worlds observation with large apature and as good as i can afford for imaging.

as a result im looking at this http://www.telescope...mbly-OTA-2.html to which i will add an EQ mount, by time you purchase everything else you need i'd expect to spend the best part of £2000, for the same money you could get an LX90 8", a 10" RC set up or a 12/14" dob or an 8/10" SCT.

personally i think this will offer me the best of both for the money

if you are thinking of a 12" scope on a GEM. Your first port of call should be to start building your obsy. There is no chance that you'll be using one without an obsy, to put it plainly a 12" scope on an EQ mount is enormous, and in no way could it be considered portable. The novelty of setting a rig

like that up every session would wear off very quickly indeed.

[Budding Star Gazer]

if you are thinking of a 12" scope on a GEM. Your first port of call should be to start building your obsy. There is no chance that you'll be using one without an obsy, to put it plainly a 12" scope on an EQ mount is enormous, and in no way could it be considered portable. The novelty of setting a rig

like that up every session would wear off very quickly indeed.

i did think of that, it would be for the back garden only and an observatory will be the best way to go but for now the kit is going to cost quite a bit so an obsy will have to come later, i guess i will hav to suffer putting it up & taking it down for a while.

[nicks90]

i did think of that, it would be for the back garden only and an observatory will be the best way to go but for now the kit is going to cost quite a bit so an obsy will have to come later, i guess i will hav to suffer putting it up & taking it down for a while.

i would dearly love to have that set up - but being practical it just wouldnt get used! The best scope is the scope you actually use, and all that....

the ota is 20kg and it needs an neq6 - another 30kg - that would be a major pain in the proverbial to lug outside and polar align and set the tube on top. By the time its set up, clouds will have rolled in and its time to knock it all down again.

[Matt Scunthorpe]

Plus OTAs can be tricky to handle, and trying to place one on the mount securely in the dark, with the weight and size may be trickier than it seems.